"DNS lookup failed" error on Google Chrome

[punchclockheroi]

Hello all,

I've frequently been receiving "DNS lookup failed" errors on Google Chrome. It seems to randomly happen, although typically it occurs every half hour or so. Most frustrating is that it happens on every computer on this network, excluding mobile devices that connect to the network.

When this does happen, other browsers can't connect either, so I know it doesn't have anything to do with Chrome itself.

http(dot)//i(dot)imgur(dot)com/gfX9F(dot)png

That's the error.

Rebooting the router usually works, but the problem comes back after a while.

IP address and DNS servers are set to be recovered automatically. Disabling network prediction has no effect. Our firewall permits Chrome. We do not use proxy servers. We've talked with our ISP and they have been unable to help us.

Any help is appreciated.

 

[DelJo63]

the domain portion is imgur.com and is valid
this is the only portion that uses DNS

the gfX9F.png is a FRAUD! I'm on Firefox and that PNG fakes a DNS lookup error
and has the Chrome logo in it

BE CAUTIOUS; you might have a virus/trojan redirection

 

[punchclockheroi]

Sorry? I screencapped the error I receive from Google Chrome, edited it in paint, and uploaded it to imgur to show.

 

[DelJo63]

my error too as I didn't recognize imgur.com as an image hosting site

 

[tipstir]

Which Router are you using? I know of a good number that have issues with DNS lookup. Still some use Open DNS instead of what your ISP DNS. I still feel routers firmware are the issue. My issue is gone now.

 

[punchclockheroi]

Our router is a Netgear WNDR3700V2.

 

[tipstir]

Oh that one.. Atheros chipset in there. Like Trendnet TEW 673GRU has the same issue WNDR3700 does with DNS. Best way to fix that is use the default IP address and leave it alone. If you change the way it is DNS issues appears. If you haven't done that then you suffer from Atheros issue with that 680MHz WNPU.

 

[xH0lyOn3x]

I have a Westell modem and I have been getting the same issue for a long time. I'll just be surfing the WWW's and i'll have a "!" pop up on my internet icon and say no internet access at random times. (windows 7) normally it will go away in a minute or two. Sometimes I'll have to restart modem. it gets really annoying especially when I'm gaming and I disconnect and die and stuff..

 

[DelJo63]

frequently Packet Fragmentation(P.F.) causes all kinds of pain.

a) determine if there is a MTU setting on the modem (or your router).

b) set it to 1492 instead of the default 1500

this will disable P.F. and make transmission more reliable.

 

[xH0lyOn3x]

a) determine if there is a MTU setting on the modem (or your router).

And how would I go about doing this?

 

[DelJo63]

first determine if there is an issue. Pick a destination (suggest google.com)

then get a command prompt and enter

• ping -F -L 1500 destingation
• the -F says do not fragment
• the -L nnnn is the ping buffer size

if you get timing data back, then this is a non-issue for that specific destination.
if you get back data fragmentation required, then reduce NNNN by multiples of 8
(eg 16,32,64,128) and try again and iterate until you find the NNNN that works for this destination.

For a DSL connection, the default MTU should be 1492 (there's 8 bytes of headers).
Once you find the NNNN that works for you, use it to configure your router's value.